1. Field of the Invention
The present invention relates to an electronic component mounting apparatus for mounting electronic components successively in prescribed positions on a mounting object, such as a circuit board, or the like.
2. Description of Related Art
FIG. 4 shows one example of an electronic component mounting apparatus of this kind. The apparatus comprises a component supplying section 16 for accommodating and automatically supplying electronic components 22, a component mounting section 18 moving in mutually orthogonal X and Y directions in order to register the position of a circuit board 17 onto which electronic components 22 are to be mounted, suction nozzle sections 120 for picking up electronic components 22 automatically supplied by the component supplying section 16 and mounting same at prescribed positions on the circuit board 17, and a head section 121 comprising a plurality of such suction nozzle sections 120 provided on the outer circumference thereof. The head section 121 is driven to rotate intermittently to prescribed halt positions, where the suction nozzle sections 120 perform the operations of picking up the electronic components 22 by suction and mounting same on the circuit board 17.
The details of the aforementioned suction nozzle sections 120 are described here with reference to FIG. 5.
The suction nozzle section 120 is supported on a guide 24 in a vertically slidable fashion and is thereby mounted on the electronic component mounting apparatus. A cam follower 30 is provided at a prescribed position in the guide section 24 in order to engage with a raising and lowering groove cam (not illustrated). On the inner portion of each suction nozzle section 120, a rotating member 31 is provided rotatably about a vertical axis with respect to the upper face of the circuit board 17 on which electronic components are to be mounted. Below the rotating member 31, there is provided a U-shaped rod section 32 which engages with the rotating member 31 via a coupling member (not illustrated) and rotates about the same vertical axis as the rotating member 31.
At the upper end of the rotating member 31, a coupling section 31a with V-shaped grooves that engages with rotational driving means (not illustrated) is provided. Below the U-shaped rod section 32, a rotating member 27 which rotates about a horizontal axis with respect to the upper face of the circuit board 17 is provided by means of a bearing (not illustrated), and a turret 25 is disposed in such a manner that it engages with this rotating member 27. A plurality of nozzle tip sections 26 are attached to this turret 25. Furthermore, engaging grooves 27a for restricting rotation are provided in the rotating member 27, along with a spring 29 which presses an engaging hook 28 capable of engaging with and disengaging from the engaging groove 27a, towards an engagement position.
This electronic component mounting apparatus is operated as described below.
The head section 121 comprising a plurality of suction nozzle sections 120 is rotated intermittently in the direction indicated by the arrow in FIG. 4. Firstly, at a component supply position of the component supplying section 16, a suction nozzle section 120 picks up an electronic component 22 by suction, whereupon the attitude of the suctioned electronic component 22 is recognized at a position corresponding to an image recognition section 19.
Depending on the attitude of the suctioned electronic component 22 thus recognized, an amount of correction for the positional registration position of the component mounting section 18, and an amount of correction for the rotation of the nozzle tip section (U-shaped rod section) 32 are calculated, in consideration of the mounting position and mounting angle for the electronic component 22 onto the circuit board 17 that are registered beforehand. The component mounting section 18 is moved and the nozzle tip section (U-shaped rod section) 32 is rotated on the basis of the calculated data (respective amounts of correction), whereupon the electronic component 22 is mounted onto the circuit board 17. In this operation, the engaging hook 28 is caused to perform a rocking movement about the fulcrum thereof, by means of a rocking movement of a lever (not illustrated) contacting one end thereof, thereby releasing the other end thereof which is engaged with an engaging groove 27a of the rotating member 27. Thereupon, the turret 25 coupled to the rotating member 27 is rotated by driving the rotating member 27 by the rotational driving means (not illustrated).
When a prescribed nozzle tip section 26 is selected, the lever (not illustrated) contacting one end of the engaging hook 28 is released by a rocking movement, whereby the engaging hook 28 is caused to engage with an engaging groove 27a of the rotating member 27 by means of the spring 29 pressing the engaging hook 28 towards the engagement position. Thereupon, at a position corresponding to a nozzle recognition section 23 in FIG. 4, image recognition of the nozzle tip section 26 is performed, and it is determined whether or not the prescribed nozzle has been selected. The series of operations described above is performed repeatedly.
However, in this conventional electronic component mounting apparatus, when selecting a nozzle tip section 26, it is necessary to halt the rotation of the head section 121 temporarily for a prescribed period of time, in order to release the engaging hook 28 from the engaging groove 27a of the rotating member 27 and rotate the rotating member 27 by the rotational driving means, and hence this is greatly disadvantageous when seeking to achieve a high-speed component mounting operation.
Moreover, since it is necessary to provide a spring 29 having a high elastic force to press on the engaging hook 28, the load on the engaging grooves 27a of the rotating member 27 and on the engaging hook 28 is high, and hence this has an adverse effect on durability.
Consequently, it is an object of the present invention to resolve the aforementioned problems by providing an electronic component mounting apparatus, whereby increased speed in electronic component mounting operations can be achieved by enabling nozzle tip sections to be selected whilst a head section is rotating, and furthermore, whereby the durability of suction nozzle sections can be improved.
In order to achieve the aforementioned object, the electronic component mounting apparatus of the present invention comprises an improved suction nozzle section that comprises a plurality of nozzle tip sections, a rod section for holding said nozzle tip sections such as to allow each of the nozzle tip sections to move upward and downward, said nozzle tip sections being disposed about the outer edge of the rod section, a motor section connected to the rod section for causing said rod section to rotate about the central axis of the suction nozzle section, a cylindrical cam section provided concentric with the rod section such as to be rotatable relative to the rod section, having a cam surface for restricting height positions of the nozzle tip sections by performing relative rotation with respect to the rod section, and a stopper section provided on an outer side of the cylindrical cam section for halting the rotation of the cylindrical cam section so as to cause only the rod section to rotate relative to the cylindrical cam section.
More specifically, the stopper section comprises a recess formed in a side face of the cylindrical cam section and an engaging section disposed engageably and disengageably with said recess. When the engaging section of the stopper section is engaged with the recess in the cylindrical cam section, only the rod section can rotate, so that, of the plurality of nozzle tip sections held by the rod section, the nozzle tip section guided by the cylindrical cam section such that it assumes a lowermost position is selected as the nozzle to be used. When the engaging section of the stopper section is not engaged with the recess in the cylindrical cam section, the cylindrical cam section rotates in conjunction with the rod section, in such a manner that the rotational position of the nozzle tip section can be corrected.
According to the present invention, by rotating the head section, electronic components are picked up from the component supplying section by suction nozzle sections, and subsequently, by further rotating the head section, the picked up electronic components are mounted at prescribed positions on a mounting object. During this operation, a nozzle tip section can be selected whilst the head section is rotating by driving the motor section, and hence no time for halting the head section is required as in the prior art, thereby making it possible to increase the speed of electronic component mounting processes. Moreover, by adopting a cylindrical cam section in each suction nozzle section, it is possible to reduce the load on the suction nozzle section in comparison to the force imparted by the spring in the prior art, and hence durability can be improved.
While novel features of the invention are set forth in the preceding, the invention, both as to organization and content, can be further understood and appreciated, along with other objects and features thereof, from the following detailed description and examples when taken in conjunction with the attached drawings.